CONTROL GP-TRANSMISSION 6K7684 - Caterpillar

Marine And Generator Set Engines (25Z, 29Z, 72Z, 73Z)The Maintenance Guides show that the oil filter elements should be changed at a differential gauge reading of 105 kPa (15 psi). The differential gauges for the oil filters on some new 3516 Engines have indicated 95 to 130 kPa (14 to 19 psi) with new oil filters. Investigation has shown that the pickup location for the filtered oil does not provide an accurate indication of the oil pressure differential. This can result in the oil filters being changed before it is necessary.
Always change the oil and filter elements at the normal recommended maintenance intervals.A production change has been made to change the pickup location for the filtered oil from the 8N3940 Elbow on the side of the cylinder block to the oil filter housing. This new location provides a more accurate indication of the oil pressure differential.
The production change is in effect with 3516 Engines 25Z459, 29Z753, 72Z319 and 73Z135. If high oil filter differential pressure is a problem on earlier engines, the pickup location for the filtered oil can be changed.
With the production change, a hole was added at the bottom of the 2W1968 Cover. This new cover must be used when changing the pickup location for the filtered oil. Use the procedure which follows to change the pickup location on earlier engines. The parts needed are shown in the chart.
1. Remove the oil filter bypass cover and install the new 2W1968 Cover (25Z1-430, 29Z1-747, 72Z1-316 engines only).2. Remove the plug and seal from the bottom of the 2W1968 Cover. Install the 3J7354 Seal, 3J7352 Connector and 7N2539 Hose Assembly in the hole in the cover. See the illustration for the location of the plug.3. Cut the former tube, that goes from the instrument panel to the 8N3940 Elbow, at a convenient location so that the new 7N2539 Hose Assembly can be easily connected to it.4. Remove both pieces of the tube. Discard the piece that was connected to the 8N3940 Elbow. Install a 9S4182 Plug in the 8N3940 Elbow.5. Flush the remaining tube to make sure it is free of debris. Install the 8L3161 Nut and 8L3162 Sleeve on the tube. Put a 37° flare on the end of the tube.6. Connect the tube to the instrument panel and to the 7N2539 Hose Assembly using the 676495 Elbow.
Location of 2W1968 Cover.